Electrical connector



NOV. 3, 1953 w HATCHER, 5 2,658,185

ELECTRICAL CONNECTOR Filed May 22, 1950 :IIII 'IHIIIII-IIII u ".Irk

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ATTORNEY Patented Nov. 3, 1953 UNITED STATES PATENT OFFICE ELECTRICAL CONNECTOR George W. Hatcher, Sr., Richmond, Va. Application May 22, 1950, Serial No. 163,370

1 Claim.

This invention relates to separable cable connectors. While the invention will be described in connection with the tractor and detachable trailer forming a load-carrying automotive vehicle, it will be clear that the invention is not limited to the particular use shown but is of utility in a wide range of facilities and applications where it is desired to provide a positive but quickly detachable connection in one or a plurality of electrical circuits.

The more important objects are (1) to provide a separable connector the parts of which can be quickly connected or separated; (2) to provide a connector in which the parts, when connected are positively locked in contacting position and which cannot be separated by vibration or road shocks; (3) to provide a connector in which the same springs act both to effect good electrical contact and to prevent separation of component parts; (4) to provide a connector in which the act of connecting the parts acts to clean the con tact surfaces thereof; and (5) to provide a connector which can be locked in position with the parts in one rotational relation only so that erroneous connection of a multi-contact connector, is prevented.

Other objects and advantages will become ap- 4 parent from a study of the following description in connection with the drawings.

In the drawings:

Figure l is a side elevation of a portion of a tractor-trailer combination showing one use for the invention in forming a disconnectable electric coupling between the tractor and trailer.

Figure 2 is a side elevational view to an-enlarged scale showing the socket and plug in locked or interengaging relation.

Figure 3 is a view corresponding to Figure 2 but showing the plug removed from its socket or receptacle.

Figure 41 is a sectional view taken upon a plane identified by line 4- of Figure 1.

Figure 5 is a longitudinal sectional view to an enlarged scale and taken in a plane identified by the line 5 -5 of Figure 4.

Figure 6 is a transverse sectional view taken upon the line 6-6 of Figure 5 showing the circumferential portions of the bayonet slots.

Figure 7 is a development of that portion of the socket embracing the bayonet slots.

Figure 8 is an end view of the multi-prong plug, and

Figure 9 is an end view of the socket with plug removed and cover plate swung to one side.

Referring in detail to the drawing, the numeral I identifies generally the tractor and 2 the loadcarrying trailer of a standard and well-known automatic vehicle combination. The numeral 3 identifies a multi-conductor cable adapted to conduct current from the tractor to the running lights and other facilities of the trailer. In the present instance, four individual conductors are shown. Inasmuch as the trailer is readily detachable from its tractor, so that the tractor may be coupled to other trailers, the cable connection 3 must be easily disconnectable.

For this purpose I have shown a socket or receptacle generally identified by the numeral 4, Figure 5, and comprisin a tubular casing 5 having an integral mounting flange 6 at one end. The flange is shown as secured by screws to a mounting plate I carried by the forward wall 2a of the trailer. The other end of the socket is closed by a plug of dielectric material 8 having a metallic ring 9 secured to its reduced inner end. This ring is a little larger in diameter than the body of the plug so that when the plug is inserted from the flanged end of casing 5, the ring 9 abuts a circular shoulder l0 formed within the casing, as shown upon Figure 5. The limiting position of plug 8 is thereby determined and it may be held in this position by any suitable means such as a set screw I I.

The plug 3 has four symmetrically arranged axial holes 12 therein in each of which a springpressed contact is located. As shown upon Figure 5, each contact consists of a thimble l3 fitting a respective hole l2 and flanged outwardly at one end. A screw I4 extends through an aperture in the other end of the thimble and is threaded into a nut l5 slidably mounted in the hole. A coil spring l6 surrounds the shank of each screw I4 and abuts the head thereof at one end and the bottom of thimble l3 at the other, whereby the spring is stressed in compression by a thrust on the end of the screw to slide the same and its nut axially within the hole. The end of each nut l5 has a flattened apertured end to receive the end of a respective cable I1. A cover l8 may be pivoted at l9 to the socket to be swung down over the opening to provide weathertight protection for the contacts when the plug is removed from the socket. The inner wall of socket casing 5 has two bayonet slots 2| and 22 formed therein each of the same general shape and extending through an effective range of However, from Figures 5 and '7 it will be noted that the bottom or axially remote end of slot 2! is positioned at lesser distance from the flanged end of easing 5 than the corresponding end of slot 22. As best shown in Figure '7, slot 22, for example, has a straight axial portion 22a, a circumferentially extending bottom portion 22b and an axially extending locking portion 22c.

The plug is generally identified by the numeral 23 and consists of a generally cylindrical body portion 24 having a central axial bore 25 counterbored to form a circular shoulder 26 axially spaced from the inner end of the plug. A contact holder 27 of dielectric material slidably fits the counterbored end of the plug body and is of a length such that when one end seats on shoulder 26 its other end is flush with the end of the plug, as shown in Figure 5. The cylindrical holder 2! may be secured in position in plug body 24 and against shoulder 26 by any suitable means such as a set screw :28, Figure-3, ThB hOldGI' 214s axially drilled-to receive -four= contact rodsifleach adapted to make electrical contact with the head of a respective screw l4 and locked in the socket. The outersendlof. each rod 29 is axially drilled to receive conductors 30 each its hole in rod 29 by set screwsas shown upon Figure 5.

The end of plug body 24 has a pair-'1 pf,; 180 spaced pins or lugs 3| and 32 each adapted to fit a respective one of the ,bayonet slots 2 l and 22 insocket casing 5. The relation ofitheparts .is such that when the plug is inserted in thejmanner shown in .FigureB, each lug rides along its slot 2! or 22 until thebottom portion s,2 lb and 2 2b-,are simultaneously reached. Prior. to, this, theend of lug portion 2'Lhas engaged'the ends pfscrews i4 andforced themaxially to tension springs 16. Then as theplug is,turned,.,each lug, rides along the bottom portion .of itsslot. Further rotation is tprevented whe ,thelugs reach the ends of the bottom portions 21b and 22121. The plug is then released and thethrustofsprings l6;act tomove the. plug axially outwardlya short distance, until thelugs-are fully seatedinthelocki portions of. the. respective bayonot slots asv indicated in Eigure'l. A semi-circular. clamp member 33 is provided and held. in position against an integral semiecircularfiange .2 d. of portion 24, byscrews 34 to clamp the, leads, 3!} in position within the body portion 24 and aid in preventing their withdrawal. If. desired.v an, insulating band, not shown, may be thusclamped' about the leads. When theplug is fullyseatedin its socket, each contact ZSJengages .onlytlieheadof a respective screw Hiso that vfour separateleadein,conductors are. providedtoefiect individual circuit connections. for any desired. facilities. or the trailer. Thus, forexample, one-,wiremay supply. all clearance lights, a-Jsecon'dwire may provide current tor-the stop lights, a third wire light and theremainingwire the leftsignal lights.

I.. have therefore. provided a. separable, multilead. connector. which can be simply. and quickly connectedand disconnected. When atrailer is hooked ,up .with ,its tractolifora haul, the plug 23 islgrasp'ed, inserted in socketfqwiththe 1ugs. 3l and .32 sliding in respective, grooyes or channels 2] and 22. Whemthe. lugs reachthe. bottomof the grooves, springs vare -.under. tensionand. after theplug isturnedthrough 90f cloclgwise, and released, the spring tension actsto translate the plug slightly outwardly. tilthe. lugs are-fully seated inaxial end portions 21c and, @2c., The aforesaid .90? rotationalso causes. a wiping action of the head oieach. screw. across itscon'tact 29, whereb the. contacts are, ,inlef fect, self cleaning. Good. electrical contacts are thereby assured whichare unaffected by vibration andrelative movement between thetractor and the trailer. In d l ll ra ed z'cege wi s u ed- When fully seated in the socket,springs lij'enert a total force of about 20. pounds on the plug. Due to the difference distances between the end of "thesocket and'the circumferential portions-of thebayonet grooves, 180 ambiguity in insertion of'the plug is impossibleand proper connection of each lead-is assured.- While theplug is thus firmly andpositively locked in operativeposition in the socket, disconnection is easily eifected by a o bi e a d t ust" i r ene d e um rclockwise t n n ql d a rai hte e when the plug is fully seated.

the ends of" of which may; beheld :within th i ht isna plug. fixed withinand closing a pull. If desired an indicator projection 35 may be provided upon the plug which extends horizontally to the right, for example; when the plug isthrust into the socket: and moves into the lower vertical position when the coupling is fully locked. When such an indicator is provided, the bayonet slots may be identical and both lugs may be at'the same distance from the end of the plug.

While I-haveshown the preferred form of the invention as now known to me, various substitutionsand modifications will occur to those skilled in tiaegrt after a study of the foregoing disclosure. Hence I do not wish to be limited to the precise detailsof construction shown; and. it is my, desire andintention to, reserve all modifications filli within the scope oithe subjoinedclaim.

I claim:

In a separable connector for electric cables, ametallic tubular. receptacle a first dielectric first endpf said receptacle, therebeing. a plurality. of axiallyextending, equally circumferentiallyspaced holes through said plug, a metallic contact slidably mounted ineach hole, meansyieldingly urging e achcontact' axially toward the second end of said receptacle, there being, a pair of. diametrically-opposite L-shaped grooves in,the internal wall of. the second end of saidmeceptacle, each said groove comprising I an axially-ext nd n p91- tionand a communicating circumferentially.ex-

tendingportion, sai Circurnferentiallwclit nding p r s lying resne t c t ans ers a ia l spaced planes along said axis, a metallic insert comprising a tubular,- endpprtioninsertable into the second endof said receptacle, apairofidiametrically opposite projections fixed externally, on said tubular end-andaxially-spaced tocorrcs-nflnd with; the axial spacing of the circumferential extending portions of said grooves, whereby/said tubularend, portion can be properly insertediinto the secondi end. ofsaid i receptacles and 1 turnedn to cause each said: projection to ride: along: tcr the end of its said circumferentiallyeextending grooves, for one-rotational relation of said-portion andt-receptacle only, to determine afinal'operative position, a second'dielectricplug closingand fixed'in the tubular. end-portion ofsaid insert, there-being a pluralityof axially-extending'circumferentially-spaced holes -in said second 1 plug each axially aligned with a respective hole-in said first plug when said plugsare in said operative relation, a plurality of metallic rods each fixed in a respective one of the holes in said secondplug. the ends of said end portion, second plugand rods being substantially flush, whereby each said metallic contact is urged against its respective rod, when said portion and receptacle are insaid final operative position, and means adaptingeach contact androdior securement theretoof'arespective one of a plurality of electrical conductors.

GEORGE HATCHER, s11.

References Cited'in the-file of" this patent UNITED STATES-PATENTS Number Name Date 1,'705;022 L'ewellen Mar. 12, 1929 1,761,436 Douglas JuneB, 1930 2,015,953 McDowell Oct; 1,- .1935

FOREIGN PATENTS Number Country Date 385,491 France Mar. 17. 1908 813,957. France Mar. .8, 1937 

